Hello World example for interfacing up to four rotary encoders to the STM32's timer/counter hardware, without interrupts.

Dependencies:   mbed-dev

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Show/hide line numbers EncoderMspInitF3.cpp Source File

EncoderMspInitF3.cpp

00001 #include "mbed.h"
00002 /*
00003  * HAL_TIM_Encoder_MspInit()
00004  * Overrides the __weak function stub in stm32f3xx_hal_tim.h
00005  *
00006  * Edit the below for your preferred pin wiring & pullup/down
00007  * I have encoder common at 3V3, using GPIO_PULLDOWN on inputs.
00008  * Encoder A&B outputs connected directly to GPIOs.
00009  *
00010  * http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00093333.pdf
00011  * http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00097745.pdf
00012  * http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00133117.pdf
00013  * Table 14 has GPIO alternate function pinout mappings.
00014  *
00015  * TIM1_CH1: AF2 @ PC_0, PE_9; AF6 @ PA_8
00016  * TIM1_CH2: AF2 @ PC_1, PE_11; AF6 @ PA_9
00017  *
00018  * (TIM2_CH1: AF1 @ PA_0, PA_5, PA_15; AF2 @ PD_3)  TIM2 is the mbed system ticker, so unavailable as encoder.
00019  * (TIM2_CH2: AF1 @ PA_1, PB_3; AF2 @ PD_4)
00020  *
00021  * TIM3_CH1: AF2 @ PA_6, PB_4, PC_6, PE_2           not for F302R8, OK @ F334R8
00022  * TIM3_CH2: AF2 @ PA_4, PA_7, PB_5, PC_7, PE_3
00023  *
00024  * TIM4_CH1: AF2 @ PB_6, PD_12; AF10 @ PA_11        not for both F302R8 & F334R8
00025  * TIM4_CH2: AF2 @ PB_7, PD_13; AF10 @ PA_12
00026  *
00027  */
00028 
00029 #ifdef TARGET_STM32F3
00030 
00031 void HAL_TIM_Encoder_MspInit(TIM_HandleTypeDef *htim)
00032 {
00033     GPIO_InitTypeDef GPIO_InitStruct;
00034 
00035     if (htim->Instance == TIM1) { //PA8 PA9 = Nucleo D7 D8
00036         __TIM1_CLK_ENABLE();
00037         __GPIOA_CLK_ENABLE();
00038         GPIO_InitStruct.Pin = GPIO_PIN_8 | GPIO_PIN_9;
00039         GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
00040         GPIO_InitStruct.Pull = GPIO_PULLDOWN;
00041         GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
00042         GPIO_InitStruct.Alternate = GPIO_AF6_TIM1;
00043         HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
00044     }
00045 #if 0 //TIM2 is the mbed system ticker
00046     else if (htim->Instance == TIM2) { //PA0 PA1 = Nucleo A0 A1
00047         __TIM2_CLK_ENABLE();
00048         __GPIOA_CLK_ENABLE();
00049         GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1;
00050         GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
00051         GPIO_InitStruct.Pull = GPIO_PULLDOWN;
00052         GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
00053         GPIO_InitStruct.Alternate = GPIO_AF1_TIM2;
00054         HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
00055     }
00056 #endif
00057 #if defined TARGET_STM32F334R8
00058     else if (htim->Instance == TIM3) { //PB4 PB5 = Nucleo D5 D4
00059         __TIM3_CLK_ENABLE();
00060         __GPIOB_CLK_ENABLE();
00061         GPIO_InitStruct.Pin = GPIO_PIN_4 | GPIO_PIN_5;
00062         GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
00063         GPIO_InitStruct.Pull = GPIO_PULLDOWN;
00064         GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
00065         GPIO_InitStruct.Alternate = GPIO_AF2_TIM3;
00066         HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
00067     }
00068 #endif
00069 #if 0
00070     else if (htim->Instance == TIM4) { // PB6 PB7 = Nucleo D10 MORPHO_PB7
00071         __TIM4_CLK_ENABLE();
00072         __GPIOB_CLK_ENABLE();
00073         GPIO_InitStruct.Pin = GPIO_PIN_6 | GPIO_PIN_7;
00074         GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
00075         GPIO_InitStruct.Pull = GPIO_PULLDOWN;
00076         GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
00077         GPIO_InitStruct.Alternate = GPIO_AF2_TIM4;
00078         HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
00079     }
00080 #endif
00081 }
00082 #endif